1. Field of the Invention
This invention relates to head stack assemblies for disk drives, and, more particularly, to an apparatus for the building of head stack assemblies from an array of head stack subassemblies that comprises an arm of an actuator having a plurality of arms, a load beam and a mounting plate, all apertured and in aperture registration for staking together with a staking tool. The invention provides apparatus that compensates for imperfectly stacked subassemblies to apply a uniform clamping pressure on the subassemblies despite one or more of the subassemblies being angled relative to the clamping nosepiece. The invention further relates to improvements in the support of mounting plates against distortion during the staking process, using spacers having substantially identical size apertures to the mounting plate apertures, rather than substantially larger as heretofore, so that the mounting plate aperture edge margins are supported by spacer aperture edge margins, and less distortion is suffered during staking, for a better head stack product. The invention further relates to methods of head stack building and to methods of aligning and supporting head stack subassemblies for staking with maximum precision and minimum mounting plate distortion.
2. Related Art
Head stacks are known, as are methods of building them from an array of head stack subassemblies. The typical head stack forming apparatus clamps an array of head stack subassemblies between a nosepiece and a baseplate. Force on the array is applied by tie nosepiece moving toward the baseplate. Spacers are provided between successive subassemblies. One function of the spacers is to support the mounting plate from becoming distorted by passage of the staking tool therethrough.